Though it’s not far from the city of Austin this wonderful nature preserve feels like you’re in another place on the planet. From the outside, it just looks like nothing but trees, but guided tours take you into a beautiful lush canyon and grotto with emerald-green waters and a 40-foot waterfall. Guided tours are available on weekends only, and it’s the only way to see the grotto. The preserve is also close to the fantastic Hamilton Pool natural spring.